Comparison of a Nuclear Polyhedrosis Virus and Chemical Insecticides for Control of the Beet Armyworm (Lepidoptera: Noctuidae) on Head Lettuce

Abstract
A multinucleocapsid nuclear polyhedrosis virus (SeMNPV) isolated from the beet armyworm (BAW), Spodoptera exigua (Hübner), was field tested and compared with methomyl and permethrin for control of BAW on head lettuce. In 3 years of testing (1980–1982), weekly population monitoring data indicated that application of the SeMNPV at a rate of 1.1 × 1012 polyhedra per ha caused BAW population reductions equivalent to those resulting from the application of methomyl (1 kg/ha) and permethrin (110 g/ha). Application of the SeMNPV at lower rates (5.5 × 1011 and 2.8 × 1011 polyhedra per ha) resulted in less effective levels of control.